This disclosure relates to gas turbine engines, and more particularly to the provision of cooling air for components of gas turbine engines.
Gas turbines hot section components, in particular turbine vanes and blades in the turbine section of the gas turbine are configured for use within particular temperature ranges. Such components often rely on cooling airflow to maintain turbine components within this particular temperature range. For example, stationary turbine vanes often have internal passages for cooling airflow to flow through, and additionally may have openings in an outer surface of the vane for cooling airflow to exit the interior of the vane structure and form a cooling film of air over the outer surface to provide the necessary thermal conditioning. Other components of the turbine often also require such thermal conditioning to reduce thermal gradients that would otherwise be present in the structure and which are generally undesirable. Thus, ways to increase thermal conditioning capability in the turbine are desired.
The internal cooling passages are typically formed in stator vanes through the use of ceramic cores during the casting process of the stator vanes. The complex geometry of the cooling passages typically prevents advantageously combining ceramic cores into a single core, which would significantly improve producibility of the stator vane. Further, as separate cores are utilized, cooling air flowed through the cooling passages is therefore fed from separate cooling airflow sources, which in many instances may not be optimal cooling air sources.